Hiya Uncle Old Duke!

Oooop, never put Dexron in an M47 or 240 power steering. Bad for Volvo M47 and bad for 240 power steering racks!

The Volvo owner manual and factory service green doc state Ford "Type F" You may also see "Type F/G" and "Type G" - each being progressively heavier lube. Ford "Type F" is relatively primitive lube without the friction modifiers to make it slippery. Like with Dexron and Mercon.

If you search for vvpete on the brickboard and turbobricks, he lays it all out as to the actual spec Volvo gear lube for M47. There is some variance between earlier M46 and later M46 so I've read.

I'd leave it to Planetman and others as for sourcing replacement syncros and other parts for M47 and other Volvo gear boxes. Planteman has the resources and, like he write, his brother has the talent to rebuild gear boxes. We hope and pray always we can source the critical parts for a successful gear box rehab every time.

Yep, my mistake. For some reason, I though Volvo used Bork and Beck gear boxes. Nope. Though am unsure.

Welp, vvpete, for M47, states using the Volvo gear lube part number 1161645. It is a full synthetic manual transmission gearbox lube specific for Volvo M47, M56, and later. I've read for M46, also. Though others argue using the Ford "Type F" in M46 as the overdrive uses hydraulic pressure from the small small piston pump, driven on shaft eccentric at the bottom of the overdrive, to engage the unit. The over drive uses some serious hydraulic PSI to do so.

Else, your best bet, as is advocated here and elsewhere, is the Redline MTL gear box lube. Go to the www.redline.com site and use the product picker tool.

vvpete also wrote that Redline is perhaps the second best choice, yet depending on how many miles and how hard you drive it, you may want to check and replace every 30k-50k miles. I'm unsure the change interval he recommends. Though vvpete does say that Redline will turn brown, indicating breakdown, in time.

I have Redline in one gear box and Amsoil SuperShift ARTQT the another two. Prior owners on these three 240s I drained the factory oil and replaced it with who knows. (Fortunately NOT Dexron, as that is a fast way to a quick M4x Volvo gear box death.)

Even with clean oil, if old, gear box oil, using the Redline (or the Amsoil), the transmissions are easy to shift and run very cool. It used to be with the three M46 transmission, they'd get so hot, as did the M47s, the heat would run up the gear shift lever on even mild temp days. Using synthetic allows them run cool by a huge gradient. If in the Summertime, it is the radiating road heat that comes up the gear shift lever if at all.

When I drained the M47II gearbox oil on the 1992 wee green beastie in like 2008, soon after buying it, the fluid was dark brown and well burnt. I gear tooth piece cam out with LOTS of silver. The fill and drain plug were FULL of silver bits. What worried me. I cleaned out the plugs, and, with it raised on the North American passenger side, I sprayed the transmission with brake parts cleaner using the red straw and sprayed through the fill hole in bursts until the drain hole came clean of waste bits. Left it to dry a day or so. Than swapped raised side for an overfill of the Amsoil. The transmission is quiet with no noise in any gear like when I bought it. Sometimes hard to shift into first gear. The synchros feel thin. A prior owner installed a high-force clamp clutch and the noisy iPd or some sort of Volvo 240 Turbo exhaust. I mean to eventually put in a front resonator or glass pack something to quiet the exhaust down, eventually.

Again, No Dexron anything in 240 manual transmission and power steering.

Dexron III (and newer, as Dexron is backwards compatible, though I wonder) for rear wheel drive Volvo auto transmission.

Unless you have a BW55 or earlier as these take Ford "Type F", iirc.

Synthetic lube is always an improvement. Synthetic can present multiple characteristics that can cross called for specifications by a thing. The Amsoil SuperShift indicates support of Ford "Type F" and Alison C-4 transmission. Alison C-4 is more Dexron-like with friction modifiers, yet is not Dexron.

Search and read up on the Volvo 240 drain and fill procedure well treated here on this forum. Use the overfill method. Ensure the fill plug unscrews first before draing. Some will use a new copper or one of the newer grey sealing crush washers. Clean the conical magnet loads of carbon steel bits in one or both of the plugs. (Brake parts cleaner and a cloth helps.)

Hope that helps.

MacDuffed.
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